Explanation:

- The sequence is built upon multiplying the previous number by increasing integers.

- Start with 7:

- \(7 \times 3 = 21\)

- \(21 \times 4 = 84\)

- \(84 \times 5 = 420\)

- \(420 \times 6 = 2520\)

- \(2520 \div 56 = 45\)

- The anomaly appears with 45, suggesting another series calculation must be used.

- The provided pattern jumps drastically; hence, assume B calculation from A.

- Consider calculating the pattern using multiplication tweaks by assuming corrections in sources.

Options:

- Option 1: 720

- Option 2: 850

- Option 3: 900 (Aligns suspect continuation pattern assumption with factorial divisions engaging symmetry)

- Option 4: 950